I often get data in various CSV files. Typically, I just want to query them for specific stuff.

For smallish datasets, I would typically open the CSV with a Spreadsheet app and then work with the data from there.

A couple of years back I figured out I could easily use SQLite instead.

It is very easy to import a CSV file into SQLite and just query it from there.

Here is an example:

$ sqlite3 :memory: <<EOF
.import --csv /tmp/data.csv mytable
SELECT AVG(value) FROM mytable;
EOF

Result:

60.2222222222222

What this command does is to start SQLite with an In-Memory database. Then it runs the command .import --csv /tmp/data.csv mytable to import /tmp/data.csv directly into a table. Because the CSV file contains column headers, the table is created automatically. Had the CSV file not contained headers, we would need to create the table manually using:

CREATE TABLE mytable (id TEXT, value INTEGER);

SELECT AVG(value) FROM mytable; calculates the average of the values in the column value.